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committed no otherwise than by mistaking for conception what is in fact inference. We have formerly shown how intimately the two are blended in almost everything which is called observation, and still more in every Description.* What is actually on any occasion perceived by our senses being so minute in amount, and generally so unimportant a portion of the state of facts which we wish to ascertain or to communicate, it would be absurd to say that either in our observations or in conveying their result to others, we ought not to mingle inference with fact; all that can be said is, that when we do so we ought to be aware of what we are doing, and to know what part of the assertion rests on consciousness, and is therefore indisputable, what part on inference, and is therefore question

able.

One of the most celebrated examples of an universal error produced by mistaking an inference for the direct evidence of the senses was the resistance made, on the ground of common sense, to the Copernican system. People fancied they saw the sun rise and set, the stars revolve in circles round the pole. We now know that they saw no such thing; what they really saw was a set of appearances equally reconcilable with the theory they held and with a totally different one. It seems strange that such an instance as this, of the testimony of the senses pleaded with the most entire conviction in favour of something which was a mere inference of the judgment, and, as it turned out, a false inference, should not have opened the eyes of the bigots of common sense, and inspired them with a more modest distrust of the competency of mere ignorance to judge the conclusions of cultivated thought.

and the perceptions on which they were grounded. Many a marvellous tale, many a scandalous anecdote, owes its origin to this incapacity. The narrator relates, not what he saw or heard, but the impression which he derived from what he saw or heard, and of which perhaps the greater part consisted of inference, though the whole is related not as inference but as matter of fact. The difficulty of inducing witnesses to restrain within any moderate limits the intermixture of their inferences with the narrative of their perceptions is well known to experienced cross-examiners; and still more is this the case when ignorant persons attempt to describe any natural phenomenon. "The simplest narrative," says Dugald Stewart,* "of the most illiterate observer involves more or less of hypothesis; nay, in general it will be found that, in proportion to his ignorance, the greater is the number of conjectural principles involved in his statements. A village apothecary (and, if possible, in a still greater degree, an experienced nurse) is seldom able to describe the plainest case without employing a phraseology of which every word is a theory; whereas a simple and genuine specification of the phenomena which mark a particular disease, a specification unsophisticated by fancy or by preconceived opinions, may be regarded as unequivocal evidence of a mind trained by long and successful study to the most difficult of all arts, that of the faithful interpretation of nature."

The universality of the confusion between perceptions and the inferences drawn from them, and the rarity of the power to discriminate the one from the other, ceases to surprise us when we consider that in the In proportion to any person's defi- far greater number of instances the ciency of knowledge and mental culti-actual perceptions of our senses are of vation is generally his inability to discriminate between his inferences

* Supra, p. 420.

no importance or interest to us except as marks from which we infer some

*Elements of the Philosophy of the Mind, vol. ii. ch. 4, sect. 5.

CHAPTER V.

FALLACIES OF GENERALISATION.

§ 1. THE class of Fallacies of which we are now to speak is the most extensive of all; embracing a greater number and variety of unfounded inferences than any of the other classes, and which it is even more difficult to reduce to sub-classes or species. the attempt made in the preceding Books to define the principles of wellgrounded generalisation has been suc

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thing beyond them. It is not the colour and superficial extension perceived by the eye that are important to us, but the object of which those visible appearances testify the presence; and where the sensation itself is indifferent, as it generally is, we have no motive to attend particularly to it, but acquire a habit of passing it over without distinct consciousness, and going on at once to the inference. So that to know what the sensation actually was is a study in itself, to which painters, for example, have to train themselves by special and long-cessful, all generalisations not concontinued discipline and application. formable to those principles might, in In things further removed from the a certain sense, be brought under the dominion of the outward senses, no present class when, however, the one who has not great experience in rules are known and kept in view, but psychological analysis is competent to a casual lapse committed in the applibreak this intense association; and cation of them, this is a blunder, not when such analytic habits do not a fallacy. To entitle an error of geneexist in the requisite degree, it is ralisation to the latter epithet, it must hardly possible to mention any of the be committed on principle; there must habitual judgments of mankind on lie in it some erroneous general consubjects of a high degree of abstrac- ception of the inductive process; the tion, from the being of a God and the legitimate mode of drawing concluimmortality of the soul down to the sions from observation and experimultiplication table, which are not, ment must be fundamentally misconor have not been, considered as mat- ceived. ter of direct intuition. So strong is the tendency to ascribe an intuitive character to judgments which are mere inferences, and often false ones. No one can doubt that many a deluded visionary has actually believed that he was directly inspired from Heaven, and that the Almighty had conversed with him face to face; which yet was only, on his part, a conclusion drawn from appearances to his senses, or feelings in his internal consciousness, which afforded no warrant for any such belief. A caution, therefore, against this class of errors is not only needful but indispensable; though to determine whether, on any of the great questions of metaphysics, such errors are actually committed, belongs not to this place, but, as I have so often said, to a different science.

Without attempting anything so chimerical as an exhaustive classification of all the misconceptions which can exist on the subject, let us content ourselves with noting, among the cautions which might be suggested, a few of the most useful and needful.

§ 2. In the first place, there are certain kinds of generalisation which, if the principles already laid down be correct, must be groundless: experience cannot afford the necessary conditions for establishing them by a correct induction. Such, for instance, are all inferences from the order of nature existing on the earth, or in the solar system, to that which may exist in remote parts of the universe; where the phenomena, for aught we know, may be entirely different, or may succeed one another according to different laws, or even according to no fixed law at all. Such, again, in mat

gree. On this subject what appeared necessary was said in the chapter on the Limits to the Explanation of Laws of Nature; but as the fallacy is even in our own times a common one, I shall touch on it somewhat further in this place.

ters dependent on causation, are all universal negatives, all propositions that assert impossibility. The nonexistence of any given phenomenon, however uniformly experience may as yet have testified to the fact, proves at most that no cause adequate to its production has yet manifested itself; When we say that the force which but that no such causes exist in nature retains the planets in their orbits is can only be inferred if we are so fool-resolved into gravity, or that the ish as to suppose that we know all force which makes substances combine the forces in nature. The supposition chemically is resolved into electricity, would at least be premature while our we assert in the one case what is, and acquaintance with some, even of those in the other case what might, and which we do know, is so extremely re- probably will ultimately, be a legiticent. And, however much our know-mate result of induction. In both ledge of nature may hereafter be extended, it is not easy to see how that knowledge could ever be complete, or how, if it were, we could ever be assured of its being so.

The only laws of nature which afford sufficient warrant for attributing impossibility (even with reference to the existing order of nature, and to our own region of the universe) are, first, those of number and extension, which are paramount to the laws of the succession of phenomena, and not exposed to the agency of counteracting causes; and, secondly, the universal law of causality itself. That no variation in any effect or consequent will take place while the whole of the antecedents re. main the same, may be affirmed with full assurance. But that the addition of some new antecedent might not entirely alter and subvert the accustomed consequent, or that antecedents competent to do this do not exist in nature, we are in no case empowered positively to conclude.

§ 3. It is next to be remarked that all generalisations which profess, like the theories of Thales, Democritus, and others of the early Greek speculators, to resolve all things into some one element, or, like many modern theories, to resolve phenomena radically different into the same, are necessarily false. By radically different phenomena T mean impressions on our senses which differ in quality, and not merely in de- |

these cases motion is resolved into motion. The assertion is, that a case of motion, which was supposed to be special and to follow a distinct law of its own, conforms to and is included in the general law which regulates another class of motions. But, from these and similar generalisations, countenance and currency have been given to attempts to resolve, not motion into motion, but heat into motion, light into motion, sensation itself into motion; states of consciousness into states of the nervous system, as in the ruder forms of the Materialist philosophy; vital phenomena into mechanical or chemical processes, as in some schools of physiology.

Now I am far from pretending that it may not be capable of proof, or that it is not an important addition to our knowledge if proved, that certain motions in the particles of bodies are the conditions of the production of heat or light; that certain assignable physical modifications of the nerves may be the conditions not only of our sensations and emotions, but even of our thoughts; that certain mechanical and chemical conditions may, in the order of nature, be sufficient to determine to action the phy. siological laws of life. All, I insist upon, in common with every thinker who entertains any clear idea of the logic of science, is that it shall not be supposed that by proving these things one step would be made towards a real

in investigating the rules of correct induction, we have had occasion to advert to the distinction between it and some common mode of the incorrect. In this number is what I have formerly called the natural induction of uninquiring minds, the induction of the ancients, which proceeds per enumerationem simplicem: "This, that, and the other A are B, I cannot think of any A which is not B, therefore every A is B." As a final condemnation of this rude and slovenly mode of generalisation, I will quote Bacon's emphatic denunciation of it; the most important part, as I have more than once ventured to assert, of the permanent service rendered by him to philosophy. "Inductio quæ procedit per enumerationem simplicem, res puerilis est, et precario concludit," (concludes only by your leave, or provisionally,) "et periculo exponitor ab instantiâ contradictoriâ, et plerumque secundum pauciora quam parest, et ex his tantummodo quæ præsto sunt pronunciat. At Inductio quæ ad inventionem et demonstrationem Scientiarum et Artium erit utilis, Naturam separare debet, per rejectiones et exclusiones debitas; ac deinde post negativas tot quot sufficiunt, super affirmativas concludere."

explanation of heat, light, or sensa-
tion; or that the generic peculiarity
of those phenomena can be in the least
degree evaded by any such discoveries,
however well established. Let it be
shown, for instance, that the most
complex series of physical causes and
effects succeed one another in the eye
and in the brain to produce a sensa
tion of colour; rays falling on the eye,
refracted, converging, crossing one an-
other, making an inverted image on
the retina, and after this a motion-
let it be a vibration, or a rush of ner-
vous fluid, or whatever else you are
pleased to suppose, along the optic
nerve a propagation of this motion
to the brain itself, and as many more
different motions as you choose; still
at the end of these motions there is
something which is not motion-there
is a feeling or sensation of colour.
Whatever number of motions we may
be able to interpolate, and whether
they be real or imaginary, we shall
still find, at the end of the series, a
motion antecedent and a colour con-
sequent. The mode in which any one
of the motions produces the next may
possibly be susceptible of explanation
by some general law of motion; but
the mode in which the last motion
produces the sensation of colour can-
not be explained by any law of mo-
tion; it is the law of colour, which
is, and must always remain, a peculiar
thing. Where our consciousness re-
cognises between two phenomena an
inherent distinction; where we are
sensible of a difference which is not
merely of degree, and feel that no add-the
ing one of the phenomena to itself
would produce the other; any theory
which attempts to bring either under
the laws of the other must be false;
though a theory which merely treats
the one as a cause or condition of the
other may possibly be true.

4. Among the remaining forms of erroneous generalisation, several of those most worthy of and most requiring notice have fallen under our examination in former places, where,

I have already said that the mode of Simple Enumeration is still the common and received method of Induction in whatever relates to man and society. Of this a very few instances, more by way of memento than of instruction, may suffice. What, for example, is to be thought of all common-sense maxims for which the following may serve as the universal formula, "Whatsoever has never been, will never be"? As, for example: Negroes have never been as civilised as whites sometimes are, therefore it is impossible they should be so.

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Women, as a class, are supposed not to have hitherto been equal in intellect to men, therefore they are necessarily inferior. Society cannot prosper without this or the other institution; e.g. in Aristotle's time, without slavery; in later times, without

an established priesthood, without artificial distinctions of rank, &c. One poor person in a thousand educated, while the nine hundred and ninetynine remain uneducated, has usually aimed at raising himself out of his class, therefore education makes people dissatisfied with the condition of a labourer. Bookish men, taken from speculative pursuits and set to work on something they know nothing about, have generally been found or thought to do it ill; therefore philosophers are unfit for business, &c., &c. All these are inductions by simple enumeration. Reasons having some reference to the canons of scientific investigation have been attempted to be given, however unsuccessfully, for some of these propositions; but to the multitude of those who parrot them, the enumeratio simplex, ex his tantummodo quæ præsto sunt pronuncians, is the sole evidence. Their fallacy consists in this, that they are inductions without elimination: there has been no real comparison of instances, nor even ascertainment of the material facts in any given instance. There is also the further error of forgetting that such generalisations, even if well established, could not be ultimate truths, but must be results of laws much more elementary; and therefore, until deduced from such, could at most be admitted as empirical laws, holding good within the limits of space and time by which the particular observations that suggested the generalisations were bounded.

This error of placing mere empirical laws, and laws in which there is no direct evidence of causation, on the same footing of certainty as laws of cause and effect, an error which is at the root of perhaps the greater number of bad inductions, is exemplified only in its grossest form in the kind of generalisations to which we have now referred. These, indeed, do not possess even the degree of evidence which pertains to a wellascertained empirical law, but admit of refutation on the empirical ground

itself, without ascending to casual laws. A little reflection, indeed, will show that mere negations can only form the ground of the lowest and least valuable kind of empirical law. A phenomenon has never been noticed: this only proves that the conditions of that phenomenon have not yet occurred in experience, but does not prove that they may not occur hereafter. There is a better kind of empirical law than this, namely, when a phenomenon which is observed presents within the limits of observation a series of gradations, in which a regularity, or something like a mathematical law, is perceptible, from which, therefore, something may be rationally presumed as to those terms of the series which are beyond the limits of observation. But in negation there are no gradations and no series: the generalisations, therefore, which deny the possibility of any given condition of man and society merely because it has never yet been witnessed, cannot possess this higher degree of validity even as empirical laws. What is more, the minuter examination which that higher order of empirical laws presupposes, being applied to the subject-matter of these, not only does not confirm, but actually refutes them. For in reality the past history of Man and Society, instead of exhibiting them as immovable, unchangeable, incapable of ever presenting new phenomena, shows them on the contrary to be, in many most important particulars, not only changeable, but actually undergoing a progressive change. The empirical law, therefore, best expressive, in most cases, of the genuine result of observation, would be, not that such and such a phenomenon will continue unchanged, but that it will continue to change in some particular manner.

Accordingly, while almost all generalisations relating to Man and Society, antecedent to the last fifty or sixty years, have erred in the gross way which we have attempted to characterise, namely, by implicitly

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